Adam D'Angelo, Founder of Quora

When Adam D’Angelo quit his job as Facebook’s CTO in January 2010, the blogosphere was buzzing. But months later, the young talent reappeared on the tech scene with a startup of his own, Q&A site Quora.

We asked him how he is building a successful company: "One thing that is really important is hiring good people. If you can get the best people, that’s a big part of being successful. Another thing is that the world changes really fast, so being able to keep up with it is really important."

Seth Priebatsch, Founder of SCVNGR

Kevin Krejci via Flickr

SCVNGR, the Boston-based Foursquare rival, made a name for itself in 2010. They've partnered with 650+ businesses including the Boston Celtics and The Boston Globe. Last week, they closed $15 million in funding.

We asked Seth what it's like to be backed by Google Ventures: "When I was in school, I was excited to study under impressive professors,” Priebatsch gushes. “Now, at SCVNGR, I’m excited to be working with and mentored by some really brilliant people.”

Tony Hsieh, Founder of Zappos

Hsieh's first company, LinkExchange, sold to Microsoft for $265 million. Shortly after the Microsoft deal, Tony discovered a company called Zappos, an online shoe and clothing store. He joined the company as an advisor and investor and eventually became CEO. Last year, a decade after selling LinkExchange, Tony sold Zappos to Amazon for $1.2 billion.

We asked Tony how he created the famously-fun Zappos work environment: "We've actually passed on a lot of smart talented people that we know can make an immediate impact on our top or bottom line. But if they're not good for our culture, which is more of a long-term play, then we won't hire them."

Dal LaMagna, Founder of Tweezerman

Dal LaMagna founded a 200-person company that generated $30 million+ in sales...after he failed at 15 prior ventures.

David Klein, Inventor of Jelly Bellies

David Klein calls himself the "real candy man." He has dedicated his life to candy entrepreneurship and is credited for inventing tasty, tiny, strangely-flavored Jelly Bellies.

We asked him how he began successfully marketing Jelly Bellies: "In the beginning it was almost impossible to get the item off the ground. I needed one big break. I called up the Associated Press and I talked to the editor of the business section and said "I have the only Jelly Bean store in the world." In 1976, the article hit the Associated Press. For some reason, it was picked up by just about every newspaper in the United States. I never had to do any selling after that. Stores were calling me saying they read about this new jelly bean."

We asked her what it's like to run a business with her family: "I've definitely seen in many cases where that just is not the smartest idea. However, the way I was raised, my father was in business with his brother and I'm super close with my family. If anything three heads, where it's me. Kourtney and Khloe, are better than one. It's good to have a numbers system where two out-rule the third person. It makes our decisions go faster.

Maria Bartiromo, CNBC anchor

Bartiromo, the famous CNBC anchor, made her big break after she ignored advice from former boss Lou Dobbs. He told her that leaving her CNN producer job to become a reporter for CNBC was the biggest mistake of her life.

We asked her why she left her great job at CNN to pursue on-air reporting: "I wanted to love what I do. You have to have self-knowledge. You have to really know yourself and know what you can do and know where your heart is. In order to be successful, you have to wake up with a fire in your belly and just want to go at it. That's the only way you'll be able to work really hard at it. I had the courage to realize what I was doing wasn't what I loved. What I loved was being in the field."

Dennis Crowley, Founder of Foursquare

Dennis Crowley sold his former company, Dodgeball, to Google. Now he is founder of a very similar company, Foursquare. Crowley walked away from an estimated $100 million Facebook acquisition earlier this year.

We asked Crowley what he learned from selling his first company: "There are definitely lessons that we learned in that first experience. Potentially selling too early, making sure that we line up the right suitors [for Foursquare], and having everyone agree on the roadmap ahead of time...Whatever path we can put the product on so that it ends up succeeding is what we really want to do."

We asked Arianna where she's expecting her company to be company five years from now: "The amazing thing about the internet is, if you say where your company will be in ten years, everyone will tell you your imagination is not big enough. So much has happened in the last five years that we could not have predicted. I think we have to take it no more than one year at a time. That means we can stay open to all the new things that are happening and integrate them into what we are doing."

Apolo Ohno, Olympic skater

Ohno is an eight-time Olympic medalist in American short track speed skating. We asked him why people fail, and what can be learned from failure: "[When people fail, you have to ask] did they really give their all? And it's a learning lesson. There were times in my life when I saw an opportunity, but I didn't give my all and it failed, or it didn't give the outcome I wanted. And in doing so, I learned from that so the next time I was stronger and I was more focused."

Want more inspiration? Check out interviews with these up-and-comers:

Brook Moreland, Founder of Fashism* - Fashism closed $1MM last fall; investors include Ashton Kutcher and Demi Moore. With well-connected stars backing her, we're sure Moreland will have celebrities using her application in no time.

Dan Leahy, Founder of Village Vines - A contender in the daily deals space, specializing in restaurants. They have spread to multiple cities nationwide and partnered with Plum Benefits since their launch just six months ago.

*Brooke is the wife of Business Insider's Deputy Editor, Joe Weisenthal.